Physikalisch-Technische Bundesanstalt

About 300 000 persons employed in Germany must wear a personal dosemeter during working hours. This does by no means concern only the staff of nuclear power plants; medicine and the technical industry also use radiation beams, for example in diagnostics and for the determination of the filling level of containers. Any radiation incident on the dosemeter gradually blackens the film inside the dosemeter so that the dosimetry centres can determine the monthly exposure of the wearer in millisievert. This unit denotes the energy of the beams deposited in the body, which is multiplied by a factor defined for the biological effect and which thus provides information about the burden on the organism. The PTB carries out research work aimed at the development of suitable dosemeters; it checks the quality of commercial measuring instruments and regularly inspects the dosimetry centres.